A pest is any animal or plant which has a harmful effect on humans, their food or their living conditions. Pests include animals which:
- carry disease-causing micro-organisms and parasites, for example, mosquitoes which carry Ross River virus and Murray Valley encephalitis.
- attack and eat vegetable and cereal crops, for example, caterpillars and grasshoppers.
- damage stored food. For example, rats and mice may eat grain in silos, rice or biscuits in shops and homes and contaminate this food with their faeces (droppings) and urine.
- attack and eat farm and station animals. For example, feral dogs (dingoes) kill or maim many sheep and goats each year; foxes will kill poultry, lambs and many species of native wildlife; and feral cats also prey on native wildlife.
- damage clothing. Silverfish, for example, eat holes in clothes.
- damage buildings. For example, termites can cause considerable damage to timber in buildings.
- bite people. For example, bed bugs (so called because they often bite people in their beds) are very difficult and expensive to control. Their bites can cause great irritation to those bitten and, like mosquito bites, can become infected if scratched.
Fig. 5.1: Some insect pests.